The present invention relates to pyrazolo-[3,4-b]-pyridine lactams which are useful as anxiolytic agents, methods for their preparation, pharmaceutical compositions containing them and intermediates used in their preparation.
In European Patent Publication No. 0094175 (see U.S. Pat. No. 4,511,568 to Bare et al.) there are described anxiolytic tricyclic derivatives of the formula I: ##STR1## in which R.sup.1 is, inter alia, alkynyl of 3 to 10 carbon atoms. However, there is no mention therein of any specific alkynyl radical as a value for R.sup.1, nor there any exemplified compound in which R.sup.1 is an alkynyl radical. It has now been discovered, and herein lies our invention, that compounds of the formula I in which R.sup.1 is a pent-3-ynyl or hex-4-ynyl radical are at least four times as potent as anxiolytic agents as the corresponding compounds which carry an n-pentyl or nhexyl radical in the same position.